Field of the Invention
This disclosure relates to a touch screen panel, in particular an electrostatic capacitive type touch screen panel dissipating static electricity to improve accuracy of touch perception.
Discussing of the Related Art
In recent years, display devices, such as liquid crystal display panels, electroluminescent display panels, and plasma display panels, which have a quick response speed, low power consumption, and an excellent color reproduction rate, have been in the spotlight. These display devices have been used for various electronic products such as television sets, monitors for computers, laptop computers, tablet computers, mobile phones, industrial terminals, personal digital assistants, and automated teller machines. In general, these display devices interface with various input devices such as keyboards, mouse devices, and digitizers. However, in order to use a separate input device such as a keyboard or mouse to perform a task on a machine including a display device, a user has to deal with the inconveniences of learning how to use it and the input device taking up space, thus making it difficult to complete the task. Therefore, the demand for input devices that are convenient and easy to use and reduce erroneous operation is growing more and more. In response to this demand, a touch screen panel for enabling a user to input information by touching the screen with their fingers or a pen was suggested.
The touch screen panel has a simple configuration capable of reducing erroneous operations. The user can also perform an input action without using a separate input device, and can quickly and easily manipulate a device through contents displayed on a screen. Accordingly, the touch sensor has been applied to various display devices.
In general, the touch screen panel is attached to a display device such as liquid crystal display, an electroluminescent display, or a plasma display panel, and is used as an input device generating sensing signals corresponding to contact positions when the screen of the display device is touched with conductive material such as fingers or pens.
Touch screen panels are classified into a resistive type, a capacitive type, an electromagnetic type and so on according to a detection method of a touched position. The resistive type touch screen panel detects a touched position by a voltage gradient according to resistance in a state that a DC voltage is applied to metal electrodes formed on an upper plate or a low plate. The capacitive type touch screen panel senses a touched position according to a difference in capacitance created in an upper or lower plate when the user touches an equipotential conductive film formed on the upper or lower plate. The electromagnetic type touch screen panel detects a touched position by reading an LC value induced as an electromagnetic pen touches a conductive film.
Hereinafter, a related art electrostatic capacitive type touch screen panel for a display device will be described with reference to FIGS. 1 and 2.
FIG. 1 is a plan view of a related art electrostatic capacitive type touch screen panel, and FIG. 2 is a cross-sectional view illustrating a region R1 of the touch screen panel shown in FIG. 1.
Referring to FIGS. 1 and 2, the related art electrostatic capacitive type touch screen panel includes an electrode part A, a routing wire part B, and a pad part C.
The electrode part A includes a plurality of first electrodes TS1 to TS4 disposed on a substrate SUB and arranged in parallel in a first direction (e.g., x-axis direction) and a plurality of second electrodes RS1 to RS5 arranged in a second direction (e.g., y-axis direction) to cross over the first electrodes TS1 to TS4.
The routing wire part B is disposed outside the electrode part A. The routing wire part B includes a plurality of first routing wires TW1 to TW4 connected to the plurality of first electrodes TS1 to TS4, respectively. Also, the routing wire part B includes a plurality of 2-1 routing wires RW1a to RW5a each connected to a first end of one of the plurality of second electrodes RS1 to RS5, and a plurality of 2-2 routing wires RW1b to RW5b each connected to a second end of one of the plurality of second electrodes RS1 to RS5.
The plurality of 2-1 routing wires RW1a to RW5a are each connected to one of the plurality of 2-2 routing wires RW1b to RW5b, which in turn are each connected to the pad part C. More specifically, the first 2-1 routing wire RW1a includes one end connected to a first end of the second electrode RS1 disposed at a first column and another end connected to the first 2-2 routing wire RW1b, which is connected to a second end of the second electrode RS1. The second 2-1 routing wire RW2a includes one end connected to a first end of the second electrode RS2 disposed at a second column and another end connected to the second 2-2 routing wire RW2b, which is connected to a second end of the second electrode RS2. In a similar manner, the third to fifth 2-1 routing wires RW3a to RW5a each have one end connected to a respective one of the third to the second electrodes RS3 to RS5 and another end connected to a respective one of the third to fifth 2-2 routing wires RW3b to RW5b. 
The second 2-1 routing wire RW2a has a crossing part intersecting the first 2-2 routing wire RW1b, the third 2-1 routing wire RW3a has crossing parts intersecting the first and second 2-2 routing wires RW1b and RW2b, the fourth 2-1 routing wire RW4a has crossing parts intersecting the first, second and third 2-2 routing wires RW1b, RW2b and RW3b, and the fifth 2-1 routing wire RW5a has crossing parts intersecting the first, second, third and fourth 2-2 routing wires RW1b, RW2b, RW3b and RW4b. 
An insulation layer is disposed at the crossing parts of the 2-1 routing wires RW2a to RW5a and the 2-2 routing wires RW1b to RW4b so that the 2-1 routing wires RW2a to RW5a are not in contact with the 2-2 routing wires RW1b to RW4b. As shown in FIG. 2, the 2-1 routing wires RW2a to RW5a have disconnection parts at the crossing part of the 2-1 routing wires RW2a to RW5a and the 2-2 routing wires RW1b to RW4b. The 2-1 routing wires RW2a to RW5a disconnected by the disconnection parts are exposed through contact holes CH1 to CH8 passing through the insulation layer INS. The 2-1 routing wires RW2a to RW5a separated by the disconnection parts are connected to each other by connection parts CP11, CP1 to CP22, CP31 to CP33, and CP41 to CP44 disposed on the insulation layer INS.
The pad part C includes a plurality of first pads TP1 to TP4 connected to the plurality of first routing wires TW1 to TW4 and a plurality of second pads RP1 to RP5 connected to the plurality of 2-2 routing wires RW1b to RW5b. An external integrated circuit, such as a controller for the touch panel, interfaces with the touch panel via the pad part C.
As mentioned in the related art touch screen panel having double routing wire construction, there are the crossing parts of the 2-1 routing wires RW2a to RW5a and the 2-2 routing wires RW1b to RW4b in the routing wire part B between the electrode part A and the pad part C.
In general, static electricity may be input to the touch screen panel while a user operates the touch screen panel. The static electricity may be input to the electrode part A via the first pads TP1 to TP4, the second pads RP1 to RP5, the first routing wires TW1 to TW4, the 2-2 routing wires RW1b to RW5b, and the 2-1 routing wires RW1a to RW5a because the first and second pads TP1 to TP4 and RP1 to RP5 have a large area and good conductivity.
If a touch event is performed on the touch screen panel while static electricity energy in the touch screen panel is high, a potential difference is generated at the crossing parts of the 2-1 routing wires RW1a to RW5a and the 2-2 routing wires RW1b to RW5b due to the touch event. Thus the static electricity is intensively introduced into the crossing parts where the potential difference is generated. That is, the crossing parts are weak to the static electricity. Accordingly, the crossing parts of the 2-1 routing wires RW1a to RW5a and the 2-2 routing wires RW1b to RW5b may be damaged by the high current due to the static electricity, thereby reducing accuracy of the related art touch screen panel to the touch event.